dev/ci: disable cluster QA again
Created by: bobheadxi
This was re-enabled in https://github.com/sourcegraph/sourcegraph/pull/31258. Unfortunately, it looks like both the tests and the deployment are unstable:
https://sourcegraph.grafana.net/goto/oqXtXMfnz?orgId=1
Test plan
No cluster-qa in main dry run: